The Awesome Megaprocessor Is Finished
Written by Harry Fairhead   
Saturday, 02 July 2016

This is a gloriously crazy idea - build a computer from scratch using transistors. No integrated circuits, just transistors. It seems like an impossible task but no - it's finished. 

You may know in theory that any computer is built of switches, but to actually build one using nothing but separately packaged transistors brings you closer to the reality.

This is what James Newman set out to do a few years ago and now it is a completed running and programmable computer. You may ask why, and to quote from James' blog:

"I didn't plan on ending up here. I started by wanting to learn about transistors. Things got out of hand."

If you don't understand how things can get out of hand you probably aren't going to appreciate this build. 

 

mega

 

Newman has built a 16-bit data/address machine with seven registers including four general purpose registers running at about 20kHz.

This is slightly more powerful than the 8-bit chips like the 6502 that the home computer revolution depended on. It only has 256 Bytes of memory, but this is limited by the total number of transistors that have to be soldered. And speaking of numbers of transistors, it took 15,300 for the processor and 27,000 for the RAM. For comparison, a 6502 had 3500 transistors in the chip.

As you can see from the video - it is big: 

 

You can program it and there is an assembler and a simulator so you can test your work. Just one word of advice, don't expect floating point.

But it does have hardware integer division.

 

ALU

 

 

 

More Information

The Megaprocessor ...

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Last Updated ( Saturday, 02 July 2016 )